A refrigeration or heating, ventilation, and air conditioning system (HVAC) system would typically include a compressor, a condenser, an expansion device, and an evaporator that form a refrigerant circuit. Such a circuit can be embodied in what is known as a chiller.
Chillers for example can be used to cool a process fluid, such as water, where such process fluid can be directly used or may be used for various other cooling purposes, such as for example cooling a space. In a cooling cycle, refrigerant vapor is generally compressed by the compressor, and then condensed to liquid refrigerant in the condenser. The liquid refrigerant can then be directed through the expansion device to reduce a temperature and can become, at least in part, a liquid/vapor refrigerant mixture (two-phase refrigerant mixture). The refrigerant, e.g. including two-phase mixture, is directed into the evaporator to exchange heat with a fluid moving through the evaporator. The refrigerant mixture can be vaporized to refrigerant vapor in the evaporator, and the refrigerant vapor can then be returned to the compressor to repeat the refrigerant cycle.